HAO Wei, HUANG Xiaogang, WANG Xin, MAO Min, YANG Yi
Under the complex sedimentary dynamic conditions of the Paleogene,the Huizhou 26-6 structure formed a complex large-scale glutenite deposit body,which was continuously accompanied by strong volcanism and associated materials,resulting in very complex lithology of the buried hill interface. At present,there are few systematic studies on the complex lithology of buried hill reservoirs,and the stuck and early warning of buried hill interfaces are also thorny issues. In order to accurately distinguish the complex lithology of buried hill reservoirs, as well as stuck buried hill interfaces to reduce engineering accidents,element logging data are used to study the complex lithology of buried hills, mainly igneous rocks,including diorite,granite,limestone and the mountain entry mode. Research shows that the main elements in Huizhou 26-6 structure include seven elements： Si,Al,Fe,Mg,K,Na,and Ca. For the main lithology of igneous in the buried hills,the four maps Si-Fe,Si-Mg,Si-Ca,Si-K have good distinguishing effects. There are two types of mountain entry modes in Huizhou 26-6 structure: one is to enter the diorite fracture development zone first and then enter the granite basement; the other is to enter the granite basement directly. The first type is when entering the diorite fracture development zone,its element characteristics are that the content of Si,K and Na elements decreases,and the content of Fe,Mg and Ca elements increases. There are subtypes in this mountain entry mode. There is a small granite intrusion developed in the weathering crust at the top of the diorite fracture development zone,which is consistent with the characteristic elements of the basement granite,but the Si and Al elements in the weathering crust are slightly higher. When entering the granite basement,the contents of Si,K,and Na elements increase,and the contents of Fe,Mg,and Ca elements decrease. The elemental characteristics of the second type are as follows： the content of Si,K,and Na elements increases,and the content of Fe,Mg,and Ca elements decreases.
